Same issue, had this since the beginning of the game.
Here is a recording I took through the PS4 share function (which means it's unrelated to any output device but the audio engine is struggling)
It happens mostly during the race in corners where there are crowds. For example in Netherlands (on the straight), or Suzuka (first chicane).
In Mexico it's basically unplayable (see video above) and this happens throughout the whole track.
Platform: PS4, Game mode: multiplayer, I tried playing around the audio settings ingame to no avail